The “Divine Lady Deity” of Yunalesca and Sophia, The Goddess’ designs are rather standard for goddess type characters. What makes them both unique, and solidifies that Yunalesca is based off of Sophia, is the fact that they’re both standing on a giant head.
Calofisteri is from FF5, and Echidna is from FF3.
It’s actually pretty smart how they designed Echidna. In FF3, Echidna is upside-down because
she’s hanging from the ceiling (or a ledge, or something). People were always wondering if they were going to incorporate that. They could have kept her exactly like that and made her immobile, but that would be kinda boring for a 24-man raid.